This invention relates to a spinning machine having spinning stations arranged on one side of the machine in a row next to one another and having depositing sites provided on the other side of the machine for sliver supply cans. The sliver supply cans each contain a sliver to be spun and devices are provided for the withdrawal of the slivers from the cans and for feeding them to the spinning stations.
In the case of a known spinning machine of this type (German Patent Document DE-C 33 25 999), the spinning stations of which are constructed as air nozzle spinning units, the slivers are withdrawn from the cans in the upward direction by means of guiding pulleys. They will then extend essentially horizontally farther to additional guiding pulleys which are arranged in the area above the drafting units of the spinning stations. In the case of the machines used in practice, the guiding pulleys are driven at circumferential speeds which are higher than the feeding speed of the drafting units. In this case, the guiding rollers, which are second in the transport direction, have a slightly higher circumferential speed than the first guiding rollers. In the case of this design, it is assumed that such guiding rollers do not achieve any slippage-free taking-along of the slivers. This is taken into account by the fact that the guiding rollers run slightly faster than would be required for the transport of the slivers. In addition, it is avoided that the slivers are tensioned which would lead to the risk of undesirable drafts (faulty drafts). These slivers hang slightly through between the guiding rollers and also between the second guiding rollers and the drafting units. Despite these measures, there is the danger of faulty drafts, particularly after fairly long stoppage times, particularly because the moisture content of the slivers will then change during the stoppage time. It is therefore virtually only possible to feed relatively coarse slivers in this manner; that is, slivers of a size of Nm 0.25 and coarser ones.
In the case of a ring spinning machine, it is also known (British Patent Document GB-PS 10 15 780) to feed the slivers to be spun in cans from which the slivers are withdrawn in the upward direction by way of rollers. The slivers are then received between two transport belts respectively and are guided by these transport belts from the cans standing in front of the spinning machines, in the downward direction, from there below the bottom to the center of the ring spinning machine, and from there upwards to the drafting units.
It is an object of the invention to develop a spinning machine of the initially mentioned type such that the risk of faulty drafts of the fed slivers is largely excluded.
This object is achieved according to preferred embodiments of the invention in that the devices for the withdrawal and the feeding of the slivers have drivable guiding belts which extend from an area above the depositing sites to the area of the drafting units.
In the case of this construction, the slivers are supported by the guiding belts virtually along the whole transport area so that they do not hang through, and thus the danger of faulty drafts is largely avoided. It is possible in this manner to bridge relatively large distances without stressing the slivers by tension or the like. In addition, it is possible by means of these guiding belts to transport the slivers almost without slippage so that, also after a stoppage, at the time of a subsequent start of the operation, the slivers are fed virtually without any slippage.
In a further development of the invention, it is provided that the spinning stations are constructed as air spinning units to which one three-cylinder drafting unit respectively is assigned, and that the cans contain slivers of a size of approximately 0.4 Nm to approximately 0.8 Nm. By means of the invention, it is possible to also feed such fine slivers in such a manner that no faulty drafts occur despite this fineness. Because of the feeding of such fine slivers, the draft inside the three-cylinder drafting units is still relatively slight and can therefore be mastered well.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.